Marine propulsion devices



April 2, 1963 Filed Dec. 30, 1959 E. LEIPERT MARINE PROPULSION DEVICES Fig.1.

'7 Sheets-Sheet l JNVENTOR.

EDWARD LEIPERT ATTORNEY April 2, 1963 E. LEIPERT MARINE PROPULSION DEVICES '7 Sheets-Sheet 2 Filed Dec. 50, 1959 IN VEN TOR.

ATTORNEY EDWARD LEIPERT April 2, 1963 E. LEIPERT 3,083,678

MARINE PROPULSION DEVICES Filed Dec. 50, 1959 7 Sheets-Sheet s Fig.5.

1N VEN TOR.

BY EDWARD LEIPERT WfZ ATTORNEY I April 2, 1963 E. LEIPERT 3,083,678

MARINE PROPULSION DEVICES Filed Dec. 30, 1959 7 Sheets-Sheet 4 H 1 E i L Z4 I47 4 e I 92 I l ii 141 Q A 1' :34 ll4 ll 10 Fig.5.

IN VEN TOR.

BY EDWARD LEIPERT ATTORNEY April 2, 1963 E. LEIPERT 3,083,678

MARINE PROPULSION"DEVICES Filed Dec. 30, 1959 '7 Sheets-Sheet IN V EN TOR.

EDWARD LEIPERT ATTORNEY April 2, 1963 E. LEIPERT 3,083,678

MARINE PROPULSION DEVICES Filed Dec. 30, 1959 7 Sheets-Sheet 6 Fig.5.

IN V EN TOR.

EDWARD LEIPERT MWWW ATTORNEY April 2, 1963 E. LEIPERT MARINE PROPULSION DEVICES 7 Sheets-Sheet 7 Filed Dec. 30, 1959 Fig.5.

Fig.5

INVENTOR.

BY EDWA;LEIPERT WW/M;

ATTORNEY I aeaasrs MARHNE PRGPULSTGN DEVIQES Edward Leipert, Put). Box 1192, Westharnpton Beach, N31. Filed Dec. 30, 1959, Ser. No. 862,949 26 Claims. (111. 115-34) This invention relates to marine propulsion devices and particularly to a mechanism in which the power to drive the propeller is taken from a point intermediate the ends of the power output shaft of an engine such as the crankshm of an internal combustion engine or the main power shaft of a turbine-type engine, and is a continuation-in-part of an application entitled Tiltable and Steerable Marine Propeller Unit, filed January 20, 1958, Serial No. 709,976, in the name of Edward Liepert, now Patent No. 2,946,306.

Presently known marine propulsion devices obtain their power by a driving connection or coupling with the end of the crankshaft or rotary power shaft of an internal combustion engine. In designs employing this type of construction, the longer the crankshaft, the more troublesome become the problems relating to torsional vibrations. Consequently, heavier shafts, more and larger bearings and greater precision in balancing must be employed. These requirements become not omy costly but add to the weight of the unit.

Accordingly, it is an object of the present invention to provide a marine propulsion device in which the driving connection from the crankshaft or rotary source of power is made intermediate the ends of said shaft thereby substantially shortening the effective length of said shaft insofar as torsional disturbances are concerned.

Another object of the present invention is to provide a marine propulsion device in which the engine is mounted in an athwartship position to provide a very compact and symmetrical unit.

A further object of the present invention is to provide a marine propulsion device which will permit a vertically disposed propeller drive to be coupled to the center section of the engine and crankshaft.

Still another object of the present invention is to provide a marine propulsion device which will permit the propeller housing section to be steered without moving the engine.

A feature of the present invention is its use of a propeller drive section coupled to an athwartship mounted engine in which the said propeller section is swingable without movement of the engine and Without requiring a partable coupling.

Another feature of the present invention is its use of an inboard engine section coupled through the hull of a boat to a swingable outboard propeller drive section.

A further feature of the present invention is its novel steering means for rotating the propeller drive housing.

Still another feature of the present invention is itsv dud exhaust system and expansion chambers incorporated within the engine support base.

A feature of the present invention is its vibration absorbing support means.

The invention consists of the construction, combination and arrangement of parts, as herein illustrated, described and claimed.

In the accompanying drawings, forming a part hereof, are illustrated three forms of embodiment of the invention, and in which:

FIGURE 1 is a view in rear elevation partially broken away to show the internal construction thereof, of a marine propulsion device made in accordance with the present invention.

FIGURE 2 is a View in side elevation partially broken away, of the marine propulsion device shown in FIGURE assets Patented Apr. 2, 1953 1, illustrating the manner in which it is secured to the stern transom of a boat.

FIGURE 3 is a view in side elevation of the marine propulsion device shown in FIGURES 1, 2, on a somewhat reduced scale, showing the manner in which it may be tilted from its drive position.

FIGURE 4 is a fragmentary view of the stern of a boat showing the manner in which the control cables are led from the marine propulsion device into the boat.

FIGURE 5 is a fragmentary view in vertical section taken through the crankshaft drive portion of a marine propulsion device made in accordance with the present invention, comprising a second embodiment.

FIGURE 6 is a view in side elevation partially broken away of a third embodiment of the present invention showing an inboard mounting of the engine.

FIGURE 7 is a view in rear elevation of the propulsion device shown in FIGURE 6 with the stern transom removed.

FIGURE 8 is a view in front elevation of the marine propulsion device shown in FIGURES 6, 7, viewed from 7 the bow of the boat.

7 showing of FIGURE 9, illustrating the resilient mounting of the marine propulsion device to the boat.

Referring to the drawings, and particularly to FIG- URES l, 2 and 3, 10 indicates the hull of a boat having bottom planking 11, and a transom 12. An engine 13 is mounted in a stationary position outboard of the stern transom 12. The engine 13 is positioned so that its crankshaft 21 is horizontally oriented and lies at right angles to the keel line of the hull 10. This transverse engine position hereafter will be referred to as lying or mounted in an athwartship position. Suspended below and supported by the engine 13 is a swingable propeller drive section 14 consisting of a rotatable gear housing 15', an elongated portion 16 of said gear housing 15, and a tubular extension 17, carrying a propeller drive housing assembly 18. It will be observed that the propeller drive section 14 is located and suspended from a point other than an end of the engine 13, and that fine suspension point lies between the two cylinders 19 and 2%. It is, however, within the purview of the present invention to suspend the propeller drive section below other than the two center cylinders of an engine. By between two cylinders, therefore, is meant, any two cylinders along the longitudinal axis of the engine crankshaft.

The gear housing 15, best shown in FIGURE 1, resembles a chamber and is constructed with opposed large bores 22, in each side. Two opposed large bushings 23 are journaled within the bores 22 and freely support the said gear housing 15, so it can rotate about the axis of the crankshaft 21. The large bushings 23 in turn, are supported by being pressed into bores 24, in the cross walls 25', and 26, of the engine crackcase 27, and are long enough to extend therethrough and into the bores 22. The bores 24, in the cross walls 25, 26, are centered on the longitudinal axis of the engine crankshaft 21. Flanges 28, on the bushings 23 locate the latter, and screws 29 hold the bushings 23 in place. The bores 22 are undercut at 31} on each side of the gear housing 15', and sealing rings 31 are pressed therein. The sealing rings 31 surround the outside of the bushings 23, and so prevent Water from leaking into the gear housing 15, or oil from leaking out. Since the lower propeller drive housing assembly 18 is attached to the rotatable gear housing 15, by means of the tubular extension 17, the said propeller drive housing assembly 18 can swing back andupwardly describing an arc, the plane of saidi' are lying in the keel plane of the boat. The propeilerr drive housing assembly 18 is of a construction such as;

is found on conventional outboard motor drives and supr ports a propeller shaft32, on.which is securedthe pro 5 peller 33.

Located within the gear housing 15, are bevel gears: 34, 35, in constant mesh. Bevel gear 34 is the driving gear? and is carried by the elongated crankshaft main journal 36, on bushings 37, 38. When the propulsion device is:

driving the boat, there is no relative movement between;

the bushings 37, 38, and the elongated crankshaft journal. 36 as will presently be shown. The crankshaft 21 shown; in FIGURE 1, is a two-piece structure comprising sections: 21a and 21b. The principal reason for using the two-- piece construction of the crankshaft 21, is to permit 1158:.

of a one-piece (rather than a split) gear housing 15, and also so that a drive disengaging means can readily be mstalled within the said housing 15. Crankshaft sectioni 21a of which the elongated main journal 36, may be an;

integral part is joined together with section 21b by means; i

of a taper 39, machined into a cylindrical extension 40,.

on the crank arm 41. A corresponding taper 42, is turned! on the free, end of the elongated main journal 36, and. threaded at the end. The sections are joined together and.

a key 43, prevents, turning on the taper'and nut 44, draws;

' trolledv When the crankshaft 21, is assembled the cylindrical extension 40, on the crank arm 41, becomes in effect, a part of the elongated crankshaft journal 36. Al

position and a spacing ring 56, slipped over the main journal 36, before the main bearing 53a is installed locates the said bearing in its correct alignment in the bushing 23. While bushing 37 is pressed into the extended hub 50, of bevel gear 34, the inner race of main bearing 53, is fitted to the outer diameter of the said hub 50, and over-runs bushing 37'. This construction substantially reduces the space required for the installation of the propeller drive section 14 and permits the engine cylinders 19,20, to be closer together thus reducing the overall length of the engine. Main bearing 53a fits onto the larger diameter 36:: of the elongated main journal and also is supported on its outer diameter by the large bushing 23.

As previously explained, the shifting fork 49 controls the lateral movement of the slidable splined sleeve 46. In this invention, shifting of the said fork 49 can be either an automatic or a manual operation. A

As shown in FIGURE 1, a lever 57 is secured to a small shaft 62" and positioned at an approximate right angle to' the shifting fork 49 held thereby, forming in effect, a bell crank. The lever 57 connects the said fork 49 to a buttonhe'ad plunger 58 slipped through a bore in the housing 15, Overlying the said plunger 58is a 59 secured to a shaft 60 which is turned by movement of an arm 61 which may be connected by rods or a cable to a remote control station (not shown). Upon movement of the lever 61, the shaft 60 will turn causing the cam 59 to depress the plunger 58. This downward movement of the plunger 58 causes the lever arm 57 to turn the shaft 62, Since the bushing 37, which is pressed into the extended hub, 50,, of the bevel gear 34, is supported by the said cyhndrlcali extension and turns on it under conditions to be explained. Bushing 38 which is pressed into the opposite extended hu 51, f b v a fit. is also u por ed d;

turns on the elongated main journal 36.

On the outer diameter of the extended hub 51, of the bevel gear 34 is cut a spur gear 52 which will mesh within I as already stated. It is to be noted that when the gears i the internal gear47 cut into the slidable splined sleeve 46,

47, 52, are out of mesh, no power will be transmitted from the engine crankshaft 21, to the driving gear 34. The crankshaft '21 will turn in the bushings 37, 38, bushing 37 becoming in .efiect a main bearing. Upon engagement of the gears 47, 52, power from the crankshaft 21 will be sent through the splines 45, on the elongated main journfl 36, and transmitted by means of the splined sleeve 46 to the driving gear 34. At this point the bushings 37, 38,1.

cease to act as bearings since there then is no relative movement between the main journal 36, and'the bushings 37, 38, because of the fact that the bevel gear 34 is tuming with the crankshaft 21, which then turns in its true main bearing 53. Movement of the shifting fork 49 will 'control the engagement or disengagement of power to the bevel driving gear 34. While a positive gear type of coupling or disengaging device has just been explained incorporated in the specific design, it is fully recognized that a friction magnetic or fluid type of clutch could be used. It will also be apparent that by employing a second vertical bevel gear opposite gear 34, for engagement with the sliding splined sleeve 46 the direction of the propeller can be reversed.

Supporting the'crankshaft 21, in the area under discussion, are two main bearings 53, 53a, straddle'mounting the elongated mainjournal 36. The main bearings 53, 53a, are, as will be seen in FIGURE 1, fitted into the large bushings 23, which in turn are supported, as previously stated, by the crankcase cross walls25 and 26. Locking rings 54, 55, retain the bearings153, 53a, in their proper fork 49. is firmly attached to the shaft 62 it will swing and move the slidable splined sleeve 46, causing disengagement of the gears 47 and 52'. The unit then will be in its neutral position.

When the pressure against lever 61 is released the coil spring 63 compressed between the face of the large diam eter portion 36a of the main journal 36 and the end of the. slidable sleeve 46 will force the said sleeve ins ore into a position which will cause the internal gear 47 on the slidable sleeve 46 to engage the external gear 52 which is integral with the bevel driving gear 34. V The unit then will be in gear and the propeller 33 will turn.

The drive disengaging mechanism of the present device will operate automatically to prevent violent spinning of the propeller 33 when, for example, the propeller drive section 14 swings upward upon striking an underwater object. Also, with this design it is impossible to engage the propeller 33 when the said propeller drive section 1 4 is tilted upward for any reason. Possible injury from a spinning propeller out of water is thus avoided. The automatic feature operates when for any reason the propeller drive section 14 is raised. As the propeller drive section 14 swings it causes the gear housing 15 to rotate. The button head plunger 58 in the top of housing 15 will be carried from the position shown in FIGURE 2 to that shown in FIGURE 3 A raised rib section or dwell 64 is formed on the inner side of a wall in crankcase 27, above the said gear housing 15. The dwell is disposed in the path of the plunger 58 as it rotates with gear housing 15. Upon contacting the dwell 64 the cam action depresses the plunger 58 thereby disengaging the drive in the same manner as it'is dis engaged by the manual control 61 When the propeller drive section 14 :is returned to its operative position the plunger 58 is rotated away from the dwell 64, and the spring 63 again causes engagement of the drive as previously explained. l 7' Lying in a substantially horizontal plane and in constant mesh with the bevel gear 34, is the driven bevel gear 35. A bearing 65 carried by the gear housing 15 supports the said gear 35 and splines 66, (see FIGURE -1) in the' oil seal 69 pressed into the gear housing and surrounding the vertical drive shaft 63, retains the lubricant in the said housing 15. A nut 79 holds the inner race of hearing 65 to the hub of gear 35. At this point it should be noted that the meshing of the bevel driving gear 34 with the driven bevel gear 35 in no way restricts the rotation of gear housing 15 since the bevel gear 35 is carried by the gear housing 15 which turns coaxially with the engine crankshaft 21 as shown in :FIGURE 2. Since gear 34 is supported by the said crankshaft 21, bevel gear 35 will move around it when the swingable propeller drive section 14 is raised.

As previously indicated, and best shown in FIGURE 1, extending below the gear housing 15 is an elongated tubular portion 16 through which runs the propeller drive shaft 68. A tubular extension 17 carrying the propeller drive housing assembly 18, is freely journaled to the said elongated portion 16, and turns for steering purposes on thin shell bushings 7.1 pressed into it, (one of which is shown). A flanged and threaded portion 72 of the elongated tubular portion 16 butts to a similar but threadless flange 72a at the upper end of the tubular extension 17. A large coupling nut 73 is slipped over the said tubular extension .17 before the flange is formed and freely secures the said extension 17, to the gear housing 15, in an operative manner. A water seal 74 is retained in a groove cut into the flange 72, and prevents possible water leakage from contaminating the lubricant in the drive housing 18.

Steering of the boat is accomplished by rotating or turning the lower propeller drive housing assembly 18, including the propeller 33. The engine 13, in this invention, unlike that of the familiar outboard motor remains stationary. To facilitate steering a drum or sheave 75 is securely fastened to the upper portion of the tubular extension 17. Several turns of the steering cable 76 are taken around the said sheave 75 and the free ends of the cable 76, are passed through grommeted bores 77, in the transom 12. The cable is then directed partially around single groove pulleys 78 (see FIGURE 4) attached to the inner side of the said transom 12, and thence through another pair of single groove, spring secured pulleys 79, offset from the pulleys 78. The cable 7 6 is then further directed through another pair of single groove pulleys 80 which are positioned more or less on a line with the transom secured pulleys 7 8. From pulleys 89 the cable 76 is led forward to a remote control station (not shown) where the cable is attached to the boats steering wheel (not shown). By referring to FIGURE 4 again it will be seen that a loop has been formed in each run of the cable 76, by the pulleys 79 which are secured in position by springs 81. If sufficient tension is put on the cables 76, the springs 81 will yield, flattening the loop and thereby give greater length to the cables 76. This additional length is required when the propeller drive section 14 is raised for any reason, (FIGURE 3 shows this clearly). In addition, the tension put on the cable 76 by the springs 81 tends to hold the drive section 1 in its proper position when in operation.

Referring again to FIGURES 1 and 2, it will be seen that a recess has been provided in the engine crankcase 27 to receive the rotatable gear housing 15 and permit it to swing. Crankcase cross walls 25, 26, form the sides of this recess. The crankcase 27 bridges the top of the cross walls 25, 26 to form a top and partial back wall 82. The front wall of crankcase 27 also spans the cross walls 25, 26, to close in the front portion 83. A recess is left at the rear and bottom as can best be seen in FIG- URE 2. This recess in the crankcase 27 is large enough to permit the required swing of the gear housing 15.

To facilitate oil drainage and permit air movement in the crankcase 27, a substantial passage indicated at 84 in FIGURE 2, is constructed between the cross walls 25, 26. This structure will also add rigidity to the crankcase 27 in this area.

There are times when lifting the propeller drive section 14, is necessary. Such occasions arise when beaching the boat, transporting it on a trailer, or inspecting the propeller for possible damage. In the embodiment shown in FIGURES 1, 2, 3, a novel ratchet type of lifting mechanism is provided. Referring to FIGURES 1, 2, a yoke passes around the forward side of the tubular extension 17 and is supported at bearing points 86, and 86a. A shaft extension 87 supported by an inverted U shaped bracket 88, between which is assembled a spring loaded ratchet gear 89, carries a lever arm 90, of substantial length. A grip 91 is fitted to the upper end of the said lever 90. When it is desired to lift the propeller section 14, the lever arm 96 is pulled toward the operator. Because of a locking device which will hold the propeller drive section 14 in several degrees of lift and hereinafter more fully explained, it is not necessary to lift the unit completely in one long sweep. Several turns on the ratchet can be taken to raise the propeller the full distance. This feature makes an easier job of lifting the propeller drive section, especially on a large size drive unit.

The means by which the propeller drive section .14 is held in a raised position is best shown in FIGURE 2. This structure is in effect, a modified ratchet. Located on the outer diameter of the rotatable gear housing 15 are several ratchet-like teeth 92. A spring loaded locking device 93, is secured by threads 94 to the engine crankcase 27. The locking device 93 consists of an enclosure 95, a flanged rod 96 extending through a bore in the said enclosure 95, and contacting the gear housing 15. A spring 97 bears against the flanged part of the rod 96, and a retaining cap 98 compresses the said spring 97 within the enclosure 95. A handle 99 is attached to the free end of the rod 96 and is pulled to release the said rod 96 from engagement with any of the teeth 92. As the 'gear housing 15 rotates, as it will when the propeller drive section 14 is raised, the spring loaded rod 96 is lifted by the ramp on a ratchet tooth 92. When the end of the said tooth ramp is reached there is an abrupt drop off behind the teeth 92, which causes the spring loaded rod to snap down behind the tooth '92 and lock the propeller drive section 14 in the lifted position. The locking feature just described also acts when an underwater object is struck with a force suificient to raise the propeller drive section 14-. Thus, after the first impact the drive is held in a raised position so no further damage to the drive section can occur.

A substantial lower end support bracket structure 100, for the propeller drive section 14 is shown in FIGURE 2. The bracket 190 is rigidly secured to the engine crankcase 27 and extends downward arching toward and in line with the tubular extension 17. A rubber lined half bearing 101 is attached at the lower end of the said bracket 1% for the purpose of holding the propeller drive section 14 in its proper position. The bearing 101 also permits easy steering and resists the reaction from the propeller thrust. This thrust reaction tends to cause the propeller drive section 14 to swing upward under the hull 10 of the boat. It will be noted that the bracket has formed on it an ear 102 into which several holes 103 are bored. By removing the clevis pin 104, slipped through a hole 103 in the said car 102, and the support arm 105 of the lower rubber mounting bracket 106, the entire propulsion unit will pivot around the substantial rod 197 extending through aligned holes 198a in the upper rubber mounting brackets 108 and the two heavy supporting ears 1G9 projecting from the engine crankcase 27. The entire propulsion unit may now be tilted to suit the rake of the transom 12 and obtain the most efficient angle of thrust from the propeller 33. When the desired tilt is determined the clevis pin 104 is replaced in the nearest hole 103 giving the desired position.

The resilient mounting brackets, best shown in FIG- URE 2, are constructed of rubber or other suitable discs sandwiched and bonded or vulcanized between fiat plates.

In the'case of the two upper brackets 108, only one of which is shown, three spaced plates are used. The center plate 110 is bent at a right angle -to form a flange 110a which is firmly bolted to the transom 12, as shown. A backing plate 111 is'suggested to stiffen the transom 12 at this point. Four rubber discs 112 are used in each of the upper brackets 108. Two of these are located on each side of the center plate 110, and the end plates 1-13 are each bonded to two of the side discs 112. It will be noted that the end plates 113 are extended beyond the rubber discs so as to receive the supporting ear 109. Holes 108a are bored through both plates 113 and the ear 109 to permit the rod 107 to pass therethrough, and join the propulsion unit to the two rubber mounted brackets 108.

The lower rubber mounted bracket 106 is of the same general construction as the upper brackets 108 but differs as follows: one bracket 106 only, is used and this employs two rubber 'discs 112. The end plates are extended outwardly further than .in the upper bracketsso as to create an arm 105. The arm 105.is set at an angle as indicated in FIGURE 2 so that in effect it causes a tortional stress in the rubber discs 112 when loaded. The purpose of this is twofold, first to give a better ride to the propulsion unit by permitting more flexing or movement under severe high speed water impact, and second to absorb the thrust impact when the engine is suddenly given full throttle. In powerful engines this sudden thrust load, concentrated over a relatively small area can overstressa transom. With the above design however, and under the above described condition the propeller unit will momentarily pivot or rock on the rod 107 and the arm 105 will yieldably resist the sudden severe thrust.

Referring again to FIGURES 1 and 2, it will be seen that the engine crankcase 27 is of one-piece or barrel type construction, it does not part anywhere on its longitudinal axis. This type of structure is to be distingu ished from the design shown in FIGURE 5.

Referring to FIGURE it will be seen that the crankcase 115 is of a two-part construction and the rotatable gear housing116 also consists of two parts, Under certain conditions this design may be more desirable. In this embodiment the engine crankshaft 117 is a one-piece structure and the disengaging mechanism shown in'FIG- URES 1 and 2has been left out of the rotatable gear housing 116 and placed elsewhere.

The engine main bearings 118, each consist of the customary two half bearings placed together to form a continuous bearing. One half of the bearing 118 is car ried in the upper portion of the crankcase 115a, and the other half in the lowerportion 11'5b. The elongated crankshaft main journal 119, shown in FIGURE 5, is straddle mounted by the said bearings 118, and thereby the crankshaft 117 is supported in the area under discussion. Bolts 120, securely hold the'crankcase sections 115a and 2115b together. It should be noted that the bearings 118 are of a length to penetrate the thickness of the crankcase cross walls 121 and extend into bores 122 in the gear housing 116. The gear housing 116 is thereby rotatably supported so that it is free to turn about an axis concentric with the longitudinal axis of the engine crankshaft 117. The two part gear housing 116 is firmly held together by bolts 123. An undercut is made in each side of the housing 116 to accommodate oil and water seals 124. The seals 124 surround the outer diameter of the bearings 118 and thereby prevent leakage at this point. The bevel driving gear 125 .may be machinedintegral with the crankshaft 117, and is in constant mesh with the driven bevel gear 126. Bearing 127 pressed over the hub 128 of the gear 126 supports and aligns the said gear and is in turn supported in a bore 129 by the gear housing 116. The propeller drive structure in this embodiment is identical to that illustrated in FIGURES 1 and2.

A third embodiment of the present invention is illustrated in FIGURES 6-10. In this embodiment the entire propulsion unit with the exception of the lower part of the propeller drive section is contained within the hull 10' of the boat. Certain beneficial results are obtained from this type of installation. A better boat balance is obtained since there is no over-hung weight and the engine and accessoriesare better protected from the 'Weather. Inboard mounting of large powerful engines also reduces the strain on the stern transom. Referring to FIGURES 6 and 7, it will be seen that the engine crankcase 27 has had a downwardly extending section 130 added to it forming a support base and carrying the entire unit. The bottom planking 11 and the stern transom 12 are cut away as indicated at '1-14, 114a. The cut-away section provides a slot-like opening in the hull 10 of the boat. The support base 130 overlies theslotted opening and is firmly secured by its flanges 130a to the planking 11, and the transom 12, in such a manner as to provide a water-tight seal between the base 130 and the hull '10. The support base 130 is provided with side walls 131 whichare formed as continuations of the cross walls 25 and 26, shown in the first embodiment, a top wall 82 similar to that shown in the first embodiment and a front wall 132 which also is actually a continuation of front crankcase wall 83, in the first embodiment. The exhaust expansion chambers 133, 133a, more fully described 'below and best shown in FIGURE 8, form a partial bottom wall 134.

a The propeller drive section 14 consistingof a rotatable gear housing 15, an elongated portion 16 and a tubular extension 17, carrying the lower propeller drive housing assembly 18, is identical to that in the first embodiment and therefore requires no further description. The engine 13 is mounted in the hull in an athwartship position,

and except for the addition of the support base 130 is the The same as that described in the first embodiment. means, both manual and automatic for disengaging the engine 13, from'the propeller drive section 14 is also identical to that in the first embodiment and therefore need not be repeated.

Steering of the boat is accomplished by rotation of the tubular extension 17 wbich'ca-rries with it the propeller drive housing assembly 18, and therefore the propeller 33. To facilitate this operation acam and lever arrangement, best shown in FIGURES 6 and 7 is employed. Two identical spacedand opposed cams135 are machined on a ring-like structure 136 which is slipped over the tubular extension 17 and securely fastened thereto. A curved lever arm 137 is disposed between the cams and secured to one end of a shaft 138. A bearing structure 139 is formed in the front wall 132 of the support base 130 and the said shaft 138 is supportedand turns therein. Since the bearing structure 13-9 may at times be submerged, a packing gland 140 is utilized to prevent water leakage into the boat at this point. A.'lever arm 14-1, securely attached to the inboard end ofthe shaft 138 serves to exert the force necessary to turn the said shaft 138 which in turn causes the outboard curved lever 7 arm 137 to bear against either of the cams 135, depend ing upon the direction of movement of the lever 141.

Upon moving the cams 135 the tubular extension 17. is turned on its vertical axis, thus steering the propeller 33;

It is to be noted that the shaft 138 lies in a fore and aft I 135 will simply move out of engagement with the curved lever arm 137 and the designis such that at any position within the steering limits of the mechanism a free pull out can be accomplished- By attaching cables (not shown) to the lever arm 141, remote steering is of course possible. On the other hand, in the event of steering cable failure,

an auxiliary extension handle 142 can be directly attached to the lever arm 141, either as a jury rig or permanent means of steering control.

From time to time it is necessary to raise the propeller drive section 14. For this purpose a cable 143 is secured at one end to the support member 144 of the cavitation plate 145. The free end of the cable 143 is then led through a pulley 146 attached to the stern transom 12 and from there to any convenient station in the stern of the boat. To raise the propeller section 14 it is only required to pull on the cable 143. A suitable knob or handle 147 is provided on the said cable. The means to hold the propeller drive section 14 in a raised position as shown in FIGURE 6, are identical to those in the first embodiment, so therefore require no further explanation.

Referring again to FIGURES 6, 7, 8, it will be seen that the exhaust expansion chambers 133, 133a, form a partial bottom 134 in the support base 130, and at the same time provide a structure to attach and firmly support the rubber lined half bearing 101 against which the thrust of the propeller 33 is taken.

It is customary with propellers operating close to the surface of the water to locate a flat plate directly over the propeller to reduce propeller cavitation. Such a plate is customarily called an anti-cavitation plate.

In FIGURES 6 and 7 there is shown an anti-cavitation plate 145 supported by an arm member 144 which is firmly bolted to the sides of the gear housing 15. When the propeller drive section 14 is swung upwardly for any reason, the plate 145 will theref re swing with the said drive section 14. The anti-cavitation plate 145 is made to loosely fit into the rear portion of the slotted opening in the bottom of the support base 13% directly over the propeller 33.

As shown in FIGURES 6 and 8-, an engine exhaust arrangement is provided whereby the exhaust gases together with the cooling water discharged from the engine cooling system are combined and directed downward through the propulsion unit support base 130, to twin underwater exhaust discharge outlets 148 which are formed into and as part of the support base 130. It is to be further noted that the exhausting means is divided into two distinct parts, forming what is commonly known as a dual exhaust system. Each of the two downwardly extending exhaust pipes 149, 150, carry the exhaust gases from all of the cylinders on their respective sides of the engine to the two downwardly leading exhaust passages 151, 152, cored or otherwise formed into the support base 130. Discharged cooling water taken preferably from the highest point in the cooling system is fed into each exhaust pipe as clearly indicated at 153, 154, in FIG- URE 8. These streams of water cool the hot exhaust gases as well as the exhaust pipes 149, 150, and provide the well known wet exhaust. The cored passage 151, 152, each terminate in the exhaust expansion chambers 133, 133a. Here the gases are further cooled and permitted to expand before entering the twin underwater exhaust discharge outlets 148. In effect, the expansion chambers 133, 133a, tend to muflle the exhaust sound by reducing the velocity of the gases as they enter the twin discharge outlets 148. The underwater discharge outlets 143 are preferably of a rectangular form being considerably higher than they are wide. The reason for this construction is that if they were of a round or square section and the boat was heavily loaded and riding deep in the water, the discharge outlets would be submerged so deeply as to create excessive exhaust back-pressure. By using an elongated opening as shown, the possibility of too deep submersion of the entire outlet is considerably reduced.

Shown in FIGURES 9 and 10, is a novel method of rubber mounting the entire marine propulsion unit of this embodiment including the support base 134 The flange 130a securing the support base 130, to the hull 10, is

formed as a loose piece, separate from the said base 139. A strip of rubber or comparable resilient material 155 of suitable cross-section is placed between the flange a, and the flangeless support base 130, and while accurately held in alignment, bonded by vulcanizing or any of the well known processes. The flange 130a in this specific design is made in two sections to facilitate assembly due to the irregular shape. It is shown at 156 in FIGURE 10, that the fiat clamped down face 139]) of the flange 139a extends slightly beyond the yieldable material 155, and the edge 130a of the support base 136. The purpose of this is to create a shear stress on the yieldable material under which type of stress excellent vibration absorbing qualities are obtainable. It is to be further noted that in bonding the flange 130a to the support base 130, a waterproof joint between the said parts is obtained. This will allow the support base 130 to be installed below the water line of the hull 10.

From the foregoing it will be seen that there has been provided a marine propulsion device which incorporates the advantages of symmetrical appearance, compactness due to the vertical propeller drive being taken from a location other than an end of the engine, a unit in which the engine remains stationary when the propeller drive section swings upwardly if an underwater obstacle is struck, and a unit which steers without need of turning the engine. In addition, an automatic propeller disengaging mechanism is shown as well as a ratchet means for holding up the propeller section. Further, greater engine efiiciency may be expected in the second embodiment of this invention due to the dual exhaust system and a smooth vibration free operation of the engine is to be expected because of the novel rubber mounting means. Much of the weight of the propulsion device has, in the second embodiment, been brought Within the hull of the vessel to improve boat balance. In the first embodiment a simple tilt adjustment of the propeller drive section is shown as well as a rubber mounting method which permits the propulsion device to ride easier.

Having thus fully described the invention, what is claimed as new and desired to be secured by Letters Patent of the United States, is:

1. A marine propulsion device comprising, a motor, a crankshaft in said motor, a propeller drive section extending from said motor, a gear housing for said drive section rotatable about the longitudinal axis of the crank shaft, and means within said gear housing to operatively couple the crankshaft at a point intermediate the ends thereof to the propeller drive section.

2. A marine propulsion device comprising, a motor, a crankcase for said motor, spaced vertical cross walls in said crankcase, a crankshaft in said motor crankcase, said crankshaft being disposed in an athwartship position, a propeller drive section extending from said motor, a gear housing for said drive section rotatable about the longitudinal axis of the crankshaft, means to freely support the gear housing within the spaced cross walls, and means within said gear housing to operatively couple the crankshaft at a point intermediate the ends thereof to the propeller drive section.

,3. A marine propulsion device comprising, an internal combustion motor, a crankcase for said motor, spaced vertical cross walls in said crankcase, a plurality of cylinders in said motor, a crankshaft in said motor within the crankcase, said crankshaft being disposed in an athwartship position, a gear housing journaled at each side to one of the cross walls, and rotatable about the longitudinal axis of the crank shaft, an elongated tubular portion on said gear housing, a propeller drive section rotatably secured to the tubular portion, and extending therefrom, and means to operatively couple the crankshaft at a point intermediate the ends thereof to the propeller drive section.

4. A marine propulsion device comprising, an internal combustion motor, a crankcase for said motor, spaced vertical cross walls in said crankcase, a plurality of cylinders in said motor, a crankshaft in said motor the crank case, said crank shaft being disposed in an athwa'rtship position, a gear housing journaled at each side to one of the cross walls, and rotatable about the longitudinal axis of the crankshaft, an elongated tubular portion onsaid gear housing, a propeller drive section rotatably secured to the tubular portion, and extending therefrom, and means to operatively couple the crankshaft at a point intermediate the ends thereof to the propeller drive section, and means to rotate the propeller drive section independently of the motor and gear housing.

5. A marine propulsion device comprising, an internal combustion motor, a crankcase for said motor, spaced vertical cross Wallsin said crankcase, a plurality of cylinders in said motor, a crankshaft in said motor within the crankcase, an elongated main journal portion in said crankshaft, said crankshaft being disposed in an athwartship position, a gear housing journaled at each side to one of the cross walls, and rotatable about the longitudinal axis of the crankshaft, said main journal portion traversing the gear housing, an elongated tubular'p'ortion on said gear housing, a propeller drive section rotatably secured to the tubular portion, and extending therefrom, and means including the elongated main journal to operatively couple the crankshaft at a point intermediate the ends thereof to the propeller drive section.

6. A marine propulsion device according to claim 5 in which the means to operatively couple the crankshaft to the propeller drive section comprises, adriving gear carried by the main journal, a driven gear in mesh with said driving gear and operatively attached to the propeller drive section, an elongated hub on the driving gear, gear teeth on the 'end of said hub, a slidable sleeve carried by the main journal portion, an internal gear in said sleeve engageable with the gear teeth on the hub, an internally splined portion on said sleeve, a splined portion on the mainjournal engaging the sleeve splines and means to shift the sleeve axially along the main journal.

7. A marine propulsion device according to claim 5 in which the means to operatively couple the crankshaft to the propeller drive section comprises, a driving gear carried by the main journal, a driven gear in mesh with said driving gear and opera'tively'attached to the propeller 'drive section, an elongated hub on the driving gear, .gear teeth on the end of said hub, a slidable sleeve carried by the main journal portion, an internal gear in said sleeve engageable with the gear teeth on the hub, an internally splined portion on said sleeve, a splined portion on the main journal engaging the sleeve splines and means comprising a forked member coupled to the slidable member, a lever on said forked member, a spring on the main journal urging the sleeve into' engagement with the driving gear hub teeth and cam means acting on the lever, to shift the sleeve axially along the main journal.

' 8. A marine propulsion device according to claim 5 'in whichthe means to operatively couple the crankshaft to the propeller drive section comprises, a driving gear carried by the main journal, a driven gear in mesh with said driving gear and operatively attached to the propeller drive section, an elongated hub on the driving gear, gear teeth on the end of said hub, a slidable sleeve carried by the main journal portion, an internal gear in said sleeve engageable with the gear teeth on the hub,'an inter- "nally splined portion on said sleeve,a splined portion on the main journal engaging the sleeve splines and means to shift the sleeve axially along the main journal, and a gear housing rotatably supported in the crankcase by a bushing penetrating a bore in each cross wall and journaled into the sides of said gear housing.

' 9, A marine propulsion device comprising, an internal combustion motor, a crankcase for 'said motor, spaced vertical cross walls in said crankcase, a plurality of cylinders in said motor, a crankshaft in said motor within the crankcase, an elongated main journal portion in said crankshaft said crankshaft being disposed in an athwart- 12 ship position, a gear housing journaled between the cross walls and rotatable about the longitudinal axis of the crankshaft, said main journal portion traversing the gear housing and cross walls, a propeller drive section rotatably secured tothe gear housing and swingable therewith through an arc, the plane of said are lying in the'keel plane of the boat, means to operatively couple the crankshaft at a point intermediate the ends thereof to the propeller drive section comprising a driving gear carried by themain journal, a driven gear in mesh with said driving gear and operatively attached to the propeller drive section, an elongated hub on the driving gear, and a slidable sleeve carried by the main. journal to couple the said main journal to the drive gear and means to support the drive gear and main journal'within the spaced cross walls comprising opposed bores in each cross Wall, a bushing in each of said bores, a main bearing in each bushing, one of said bearings directly supporting the main journal section, a drive gear hub portion carried by the other main bearing and bearing means within the cross wall bore between the gear hub portion and the main journal to support the main journal therein, and an outboard bearing within a second extended hub of the drive gear freely embracing the main journal to further support the said drive gear. 1

10. A marine propulsion device comprising a motor, a crankcase for said motor, a recess in said crankcase, said recess having side walls, a front wall and a top wall, a gear housing swingably carried within the recess, a propeller drive extending from the gear housing, a crankshaft in said motor traversing the crankcase and gear housing,

and means to operatively, couplethe crankshaft at a point intermediate the ends thereof to the propeller drive section. :11. A marine propulsion device comprising a motor, a

crankcase for said motor, a recess in said crankcase, said recess having side walls, a front wall and a top wall, a raised rib in said top wall, a gear housing swingably carried within the recess, a propeller drive extending from the gear housing, a crankshaft in said motor traversing the crankcase and gear housing, means to operatively couple the crankshaft to the propeller drive section, and means to disconnect the crankshaft from the propeller drive including a plunger carried by the gear housmg and engageable by the raised rib in the top wall.

crankcase for said motor, a recess in said crankcase, said recess having side walls, 'a front Welland a top wall, a

12. A marine propulsion'device comprising a motor, a

gear housing swingably carried Within the recess, a propeller dr1ve extending from the gear housing, means to lift the'propeller drive from its-operative position comprising a yoke embracing the said propeller drive and an arm connected to said yoke, a crankshaft in said motor traversing the crankcase and gear housing, and meansto operatively couple and a ratchet gear between the arm and yoke, a crankshaft in said motor traversing the crankcase and gear housing, and means to operatively couple the'crankshaft to the propeller drive section.

14. A marine propulsion 'device' comprising a motor, a crankcase for said motor, a recess in said crankcase, said recess having side walls, a front wall and a top .wall, a spring loaded locking device carried by a wallof said recess and extending inwardly thereof, a gear housing swingably carried Within the recess, a plurality of buttressed teeth on said housing engageable with thelocking device to hold thepropeller drive section in ancievated position, a propeller drive extending from the gear housing, means to lift the propeller drive from its operative position comprising a yoke carried by the crankcase and embracing the said propeller drive, an arm connected to said yoke and a ratchet gear between the arm and yoke, a crankshaft in said motor traversing the crankcase and gear housing, means to operatively couple the crankshaft to the propeller drive section.

15. A marine propulsion device according to claim in which the crankcase is provided with a passage traversing the recess and communicating with the interior of said crankcase.

16. A marine propulsion device for a boat comprising a motor mounted outboard of said boat in an athwartship position, resilient mounting means for the propulsion device, a crankcase for said motor, a recess in said crankcase, said recess having side walls, a front wall and a top wall, a raised rib in said top wall, a gear housing swingably carried within the recess, a propeller drive depending from the gear housing, a crankshaft in said motor traversing the crankcase and gear housing, said gear housing being swingable about the longitudinal axis of the crankshaft, means to operatively couple the crankshaft to the propeller drive section, and means to disconnect the crankshaft from the propeller drive including a plunger carried by the gear housing and engageable by the raised rib in the top wall.

17. A marine propulsion device, according to claim 16, in which the resilient mounting means comprises at least one upper and one lower assembly, each consisting of a flanged plate attached to the stern transom, a resilient element bonded to each side of said plate, spaced end plates bonded to the outer surfaces of said resilient elements, and a bore in each of said end plates for pivotal supporting connection with the propulsion device.

18. A marine propulsion device, according to claim 16, in which the resilient mounting means comprises at least one upper and one lower assembly, each consisting of a flanged plate attached to the stern transom, a resilient element bonded to each side of said plate, spaced end plates bonded to the outer surface of said resilient elements, a bore in the upper assembly end plates for pivotaL ly connecting the upper assembly to the propulsion device, a bore in the lower assembly end plate, means including a bracket secured at one end to the crankcase, and depending therefrom in the direction of the propeller drive section, a resilient lined half bearing on the free end of the bracket to support the propeller drive section, an ear on the bracket, a plurality of holes in said ear, and a pin received within the end plate bore and one of the ear holes to adjustably couple the lower mounting device to the rigid arm.

19. A propulsion device for a boat having a slot-like opening in the stern transom and bottom planking there of comprising a motor, a crankcase for said motor, a downwardly extending base portion on said crankcase, means to secure the crankcase and base portion inboard of the stern transom and bottom planking in watertight engagement therewith and overlying the said slot-like opening, a gear housing swingably carried within the crankcase recess, a propeller drive section depending from the gear housing and extending below the bottom planking, a crankshaft in said motor traversing the crankcase and gear housing and means to operatively couple the crankshaft at a point intermediate the ends thereof to the propeller drive section.

20. A propulsion device for a boat having a slot-like opening in the stern transom and bottom planking thereof comprising a motor, a crankcase for said motor, a downwardly extending base portion on said crankcase, a recess in said crankcase and downwardly extending portion, said recess having spaced side walls, a front Wall and a top Wall, means to secure the crankcase and base portion inboard of the stern transom and bottom planking in watertight engagement therewith, and overlying the said slot-like opening, a gear housing swingably carried within the crankcase recess, a propeller drive section depending from the gear housing and extending below the bottom planking, a crankshaft in said motor mounted in an athwartship position traversing the crankcase and gear housing and means to operatively couple the crankshaft at a point intermediate the ends of said crankshaft to the propeller drive section.

21. A propulsion device for a boat having a slot-like opening in the stern transom and bottom planking thereof comprising a motor, a crankcase for said motor, a downwardly extending base portion on said crankcase, a recess in said crankcase and downwardly extending portion, said recess having spaced side walls, a front wall and a top wall, means to secure the crankcase and base portion inboard of the stern transom and bottom planking in watertight engagement therewith and overlying the said slot-like opening, a gear housing swingably carried within the crankcase recess, a propeller drive section rotatably secured to and depending from the gear housing and extending below the bottom planking, steering means comprising spaced cams carried by the propeller drive section, a lever arm between the propeller drive section and front wall of the recess, said lever arm being freely received between the cams and means to swing the lever arm so as to bear upon the cams to rotate the propeller drive section, a crankshaft in said motor mounted in an athwartship position traversing the crankcase and gear housing, and means to operatively couple the crankshaft to the propeller drive section.

22. A propulsion device according to claim 21 in which the lever arm is curved outwardly and is carried on the outboard end of a shaft journaled in the front wall of the recessed base and a control lever arm secured to the inboard end of said shaft.

23. A propulsion device according to claim 19 in which the crankcase and base support securing means comprises a flange-like member, a resilient element bonded on one side to the flange and on its other side to the outside of the end portion of the crankcase and base support defining the recess and means to fasten the flange to the boat.

24. A propulsion device according to claim 20 in which the engine is provided with an exhaust system comprising at least one engine exhaust manifold, at least one exhaust passage formed within a wall of the engine support base, said exhaust passages terminating in an expansion chamber, means to connect the exhaust passage to the manifold, said expansion chamber being formed as a part of the engine support base, a rectangular shaped tubular member connected to each end of the said expansion chambers for discharging the exhaust gases, said rectangular members being disposed to lie below the water level and means to discharge the engine cooling water into the exhaust system.

25. A propulsion device for a boat having a slot-like opening in the stern transom and bottom planking thereof comprising a motor, a crankcase for said motor, a downwardly extending base portion on said crankcase, a recess in said crankcase and downwardly extending portion, means to secure the crankcase and base portion inboard of the stern transom and bottom planking in watertight engagement therewith and overlying the said slot-like opening, a gear housing swingably carried within the crankcase recess, a propeller drive section depending from the gear housing and extending below the bottom planking, a propeller on the end of the drive section and an anti-cavitation plate carried by the propeller drive section directly over the propeller and substantially covering the bottom of the crankcase and base portion recess, a crankshaft in said motor traversing the crankcase and gear housing and means to operatively couple the crankshaft to the propeller drive section.

26. A propulsion device according to claim 20 in which the engine is provided with exhaust manifolds, the front wall is formed with elongated exhaust passages therein 15 connected to the exhaust manifolds, the base portion is provided with exhaust expansion chambers connected to the exhaust passages, said expansion chambers supporting a resilient lined half-bearing bracing the propeller drive section against propeller thrust reaction.

References Cited in the file of this patent UNITED STATES PATENTS 2,209,301 Johnson July 23, 1940 16 Schmitter Feb. 6, 1945 Waterhouse et a1. -V-V-H--- July 2, 1957 Leipert May 17, 1960 Leipert July 26, 1960 FOREIGN PATENTS Great Brita-in Nov. 22, 1923 Austria Nov. 25, 1931 France Dec. 6, 1948 

1. A MARINE PROPULSION DEVICE COMPRISING, A MOTOR, A CRANKSHAFT IN SAID MOTOR, A PROPELLER DRIVE SECTION EXTENDING FROM SAID MOTOR, A GEAR HOUSING FOR SAID DRIVE SECTION ROTATABLE ABOUT THE LONGITUDINAL AXIS OF THE CRANKSHAFT, AND MEANS WITHIN SAID GEAR HOUSING TO OPERATIVELY COUPLE THE CRANKSHAFT AT A POINT INTERMEDIATE THE ENDS THEREOF TO THE PROPELLER DRIVE SECTION. 